As he played out the final year of his rookie contract, the 2019 season couldn't have gone much worse for Mariota. He opened as the Tennessee Titans' starting quarterback but lost the job to Ryan Tannehill by Week 7.
Making matters worse, the Titans looked like a different team with Tannehill under center. They closed with a 7-3 record and earned a wild-card berth en route to the AFC Championship Game.
Mariota was a non-factor in the postseason. His most notable contribution came as a decoy on Derrick Henry's touchdown pass to Corey Davis against the Baltimore Ravens in the divisional round.
Although crediting the quarterback change as the sole reason for Tennessee's turnaround would be reductive, the contrast between Mariota's and Tannehill's final numbers was impossible to ignore.
- Mariota: 1,203 yards, seven touchdowns, two interceptions, 7.5 yards per attempt, 59.4 percent completion rate
- Tannehill: 2,742 yards, 22 touchdowns, six interceptions, 9.6 yards per attempt, 70.3 percent completion rate
In general, Mariota's NFL career has been disappointing since the Titans selected him second overall after Jameis Winston in the 2015 draft. He has thrown for 13,207 yards, 76 touchdowns and 44 interceptions while completing 62.9 percent of his passes.
Mariota only missed two games in 2018 but battled a nerve issue in his right arm throughout the year, which left him at less than 100 percent. As a result, his passing yards per game fell from 215.5 in 2017 to 180.6.
ESPN's Turron Davenport also hit on what has been a persistent issue. Mariota has been sacked 155 times in 63 games, a number that can't be blamed only on the Titans offensive line:
"It's not all Mariota's fault, but the Titans have allowed an NFL-high 25 sacks — including 12 over the last two weeks. According to NFL Next Gen Stats, Tennessee's offensive linemen have actually been pass-blocking well at times, sustaining their blocks for at least 2.5 seconds 62% of the time this season — good for fifth best in the NFL per ESPN's Pass Block Win Rate.
"Part of the problem is Mariota is averaging 2.84 seconds before throwing passes, the ninth-longest average time in the NFL. And when the Titans' offensive line doesn't give up a pass block win (rusher beating a block within 2.5 seconds), Mariota's Total QBR of 42.8 ranks 29th out of 30 qualified quarterbacks. Only Dolphins quarterback Josh Rosen had a worse rating."
Making a firm judgment about Mariota's performance is still somewhat difficult, though.
Lamar Jackson is a perfect example of how the right coaching staff can elevate a quarterback who has skills beyond that of a traditional pocket passer. The Baltimore Ravens found ways to tailor the offense to Jackson, and he was the NFL's Most Valuable Player.
Mariota didn't have that luxury in Tennessee. Neither Ken Whisenhunt nor Mike Mularkey thought outside the box much when they were leading the Titans through his first three seasons.
Henry was becoming the focal point of the offense as a result, and the acquisition of Tannehill indicated Mike Vrabel was losing faith in the incumbent starting quarterback.
The 2014 Heisman Trophy winner turns 27 in October. Kirk Cousins was 27 when he took over as the Washington Redskins' Week 1 starter in 2015. Jimmy Garoppolo was 26 when he made his first start for the San Francisco 49ers.
There's still time for Mariota to rewrite his career narrative, starting with the Raiders.
After making three straight Pro Bowls between 2015 and 2017, Derek Carr has largely stagnated. He's too good to be considered among the league's worst quarterbacks but not good enough to truly crack the elite tier.
Carr's long-term future with the team has been a storyline throughout Jon Gruden's first two seasons as head coach. The Athletic's Jay Glazer argued the Raiders should pursue Tom Brady to generate some excitement as they prepare for their first year in Las Vegas.
Mariota is obviously a step down from Brady, but landing the future Hall of Famer was always a long shot.
This move likely buys Carr one more season to make significant strides; otherwise, he could be moving on. The Raiders would save almost $19.7 million and absorb $2.5 million in dead money by cutting him next offseason, per Over the Cap.